Method of and apparatus for feeding molten glass



Sept. 14, 1937. F, l.. o. wADswoRTH METHOD OF AND APPARATUS FOR FEEDING MOLTEN GLASS Filed Jan. 23, 1955 2 SheeS-Shee'f;y 1v

y I INVENTORS um mm Sept- 14, 1937- lF. L. o. WADswoRTH Y 2,093,373

METHOD OF AND APPARATUS FOR FEEDING MOLTEN GLASS Filed Jan. 23, 1953 2 )Sheets-Sheet 2 o o INVENTOR Patented Sept. 14, 1937 UNiTED STTS METHOD 0F AND APPARATUS FOR FEEDING MOLTEN GLASS Frank L. 0. Wadsworth, Pittsburgh, Pa., assigner to Ball Brothers Company, Muncie, Ind., a corporation of Indiana Application January 23, 1933, Serial No. 653,081

21 Claims.

My invention relates to improvements in the art of delivering successive charges of molten glass, or similar material, to the molds or other receptacles in which they are subsequently shaped to iinal form; and, stated generally, the main objects of these improvements are to increase the speed of the delivery operations, and improve the character of the successively delivered mold charges; and to also simplify the apparatus with which these operations are performed.

Stated more specifically, some of the purposes of my present invention are to prevent any sensible loss of time between the cutting off and delivery of each mold charge and the beginning of the formation of the succeeding charge-by reducting the duration and the amount of the retardation imposed on the outfiowing glass during the cutting olf or severing interval; to increase the speed of the severing action itself, and thus reduce the momentary chilling of the molten material by its Contact with the shear blade or severing means; to est-ablish and maintain a better or more effective control on the delivery of the glass in the intervals between successive severing actions and thus obtain more complete control of the weight and shape of the successively formed charges; to maintain greater uniformity or constancy of temperature conditions in the mass of material from which the charges are formed (and thereby minimize the detrimental effect of temperature variations both on 1 the delivery oper-ations and on the subsequent fabrication of the delivered charges) and to provide improved means for the attainment and accomplishment of the various objects above enumerated.

Another object of this invention is to provide means for automatically eliminating or minimizing the effects of various changes in operative conditions during the continued operation of the feeder mechanism.

A further purpose of the present improvements is the provision of improved instrumentalities which will permit the operator of the feeder to, at any time, vary and regulate the action of various operative elements so as to obtain and maint-ain the desired character of delivery, and secure the requisite weight and form of mold charges for the formation of any given article.

Another specific object of this invention is to provide means for preventing or minimizing the escape of hot gases of combustion from the heated chamber from which the molten material is de livered, and the impingement of those hot gases'- on the portions of the apparatus which are outside of that chamber.

An additional purpose of my improvements is to provide an apparatus of such character as to permit vof the easy removal and replacement of those parts which are paraticularly subject to breakage or deterioration.

Still another object of the improvements herein described is the elimination of certain elements heretofore used in other forms of feeding mechanism; and the consequent simplification of the construction as a Whole.

Various other ancillary objects and purposes of my improvements will be apparent, to those skilled in this art, by the following description of the illustrative embodiment of my invention which is depicted in the accompanying drawings, in which:

Figs. 1, 2, and 3-are semi-diagrammatic illustrations of the general method of procedure which I follow in the practice of this invention, and of the main parts of the apparatus which I employ in this practice.

Fig. 4 is a vertical section, on a central longitudinal plane, of one of the structural embodiments of my improvements; Fig. 5 is a partial horizontal section, on the plane V-V of Fig. 4 of this construction; Fig. 6 is a front elevation of this apparatus as viewed at right angles to the sectional plane of Fig. 4; and Fig. 'I is a detail side View (partly in section) of apart of the construction shown in Fig. 6.

Figs. 1, 2, and 3 diagrammatically illustrate the major features ofmy present improved method, or mode of procedure, for feeding glass from a main source or paren body of the molten materi-al;l and generally described, this method comprises; the segregation, or p-artial connement, of a relatively small portion (A) of glass, in the interiorV of an inverted cup or bellsuch as that indicated by B-which is positioned with its lower open end above a delivery orifice (F) in the floor of the receptacle, or chamber C that contains the parent bodyof material; and which is capable of kvertical'reciprocationin a line substantially parallel e to the axis of this orice; the trapping or conningpof a Xed or predetermined quantity of elastic fluid (e. g. air) in the space (D) between the upper surface of the segregated mass Y(A) and thefupper end of the cup or bell (B) and the varying of the volume and the pressure of this trapped mass of elastic fluid by the vertical reciprocatory movement of the container, which concurrently varies the area of the opening or passageway GfA leading from the main receptacle to the segregation chamber in the cup or container (B).

More specifically described the procedure is as follows: At some definite position, or point of movement, of the reciprocable bell, the stop cock E-Which is located in a small pipe connection, e, that leads from the upper end of the bell to a suitable source of elastic fluid (either the external atmosphere, or a tank containing compressed or rareed air)-is momentarily opened, and a fixed mass or quantity of this elastic fluid is thus admitted to the space above the glass in the segregation chamber. The cock is then closed, thus trapping this predetermined amount of iiuid in the closed upper end of the bell; and the up and down movement of the latter then tends to progressively increase or decrease the volume (and consequently diminish or augment the pressure) of this confined body of fluid and correspondingly raise or lower the level of glass in the segregation chamber.

It will be clearly understood that this action is not dependent upon any mechanical adhesion of the molten material to the surface of the reciprocating container (B) -which is the major factor in the operation of the sticky plunger feedernor is it due to any alternate admission and withdrawal of air, to and from, the bell cavitywhich is the controlling effect in the operation of the ordinary air feeder-but is due primarily (and in certain cases solely) to the maintenance of a hydrodynamic equilibrium between the glass outside and inside the moving container. This condition of automatically established equilibrium supplements the action of gravity in determining and controlling the outflow, or rate of discharge, of the molten material through the delivery outlet F; and consequently regulates both the weight and the shape of each charge of glass which is cut off from the outfiowing stream by the severing mechanism.

If the cock E is opened tothe external air when the bell B is in any definite position or point in its movement-e. g., the position shown in Fig. l-the glass in the segregation chamber will assume, or tend to assume, the same level (H) as that in the main receptacle. If this cock is turned so as to put the space, D, in communication with a reservoir containing air under pressure, the corresponding level of the glass in the chamber will be depressed (as indicated by the dotted line H1), but if this reservoir contains rarefled air, this level will be raised (as indicated by the dotted line H2). This` level (H, H1 or H2) which is established by the momentary opening of the cock E at a predetermined position of the bell-may, for convenience, ybe termed the starting level or the neutral level of the glass in the segregation chamber. In this position glass is flowing from the main body of material, under the lower edge of the bell-through the passage G-and out through the orifice F under the action of gravity alone; and this gravity flow has no effect on the glass in the segregation chamber unless the passageway G is so restricted as to offer a relatively high resistance to the movement of the molten material. But when the cock E is closed and the bell B is moved downward-` toward the position shown in Fig. 2-the fixed mass of trapped fluid in the chamber D exerts a dynamic pressure on the mass of glass below it, and thereby supplements the effect -of gravity in accelerating the outflow from the delivery opening.

The increased pressure y on the glass in the downwardly moving cup or bell B, will force portion of the segregated mass outwardly through the passage G, and back into the parent body of material in the main receptacle C-in opposition to the gravity flow from the said parent body to the Aoutlet F-but this reverse flow will be progressively reduced, and the percentage of pressure induced flow through F progressively augmented, by the continued reduction of the area of the passage G by the downward movement of the container. At the end of the downward movement-when the end of the container is close to the floor of the main receptacle-the flow of glass through the passage G is almost completely arrested and the discharge of glass from the delivery outlet is controlled almost entirely by the pressure in the chamber D.

If molten glass had no viscosity and no inertia-or if the movement of the container is relatively slow-the depression of the level in the downwardly moving bell would (in accordance with the laws of hydrostatic equilibrium) be substantially the same as that downward movement itself. But owing to the fact that glass at its normal working temperature is quite viscous-and therefore offers a substantial resistance to any rapid current movementsand owing to the further fact that glass is much heavier than water; the movement of the material in the segregation chamber will lag behind the movement of the container; and the pressure in the trapped mass of fluid above the glass will, in consequence of this, build up more or less rapidly as the downward movement continues, and will normally reach a maximum at the end of that movement. The flow of glass from the delivery outlet will thus be continually accelerated, during the descent of the member B; and this accelerated ow will continue for a sensible period after the termination of the downward stroke, because of the accumulated pressure in the mass of trapped and compressed fluid (D) in the segregation chamber.

In this respect the results obtained by my improved mode of procedure are different from, and superior to, those obtainable by the use of a reciprocating plunger which throttles, and to that extent retards the discharge of glass from the delivery outlet during the latter portion of the down stroke, and which does not have, and cannot have, any expelling action after the downward movement ends.

When the cup or bell begins to rise it will tend to relieve or reduce the pneumatic pressure on the glass immediately above the orifice, and this will diminish, but will not arrest, the outflow therefrom under the action of gravity. This diminution in the rate of discharge will result in a corresponding contraction, or a natural necking, of the flowing stream, so that it may then be more readily severed by the cutting mechanism. But this momentary diminution or retardation in the outflow of glass from the segregation chamber (A-D), will be quickly compensated, or corrected, by the rising movement the positive withdrawal of the air from the air bell results in the complete arrest, or even a reversal of the delivery flowand it will also Yoccur more quickly than in the. standard type of sticky plunger feeder (e. g. as disclosed in the Brookfield, or Morrison Patent Nos. 836,297 and 810,167) where the upward movement yof the plunger may and, as a rule does, result in the' arrest and the lifting of the vglass between the shearing plane `and the outlet orifice.

The operation of my improved feeder is thus broadly distinguished from the action of previous forms of forced flow feeders-of either the reciprocating plunger or the lfluid impulse type.- in which there is a complete arrest or even a reversal of iiow at periodic intervals; and a consequent loss of time, and an accompanying decrease in delivery capacity during such intervals.

Referring now to the form of construction shown in Figs. 4, 5, 6, and '7; I indicates a forehearth extension or dog house, which extends out from the front of a glass melting tank 2, and which is provided near its front end with a submerged delivery outlet F; and which is also provided with gas or oil burners 3-3 etc., for maintaining the glass in the iorehearth at the desired working temperature.

The reciprocable cup or bell B, which is positioned above the discharge orifice F comprises a refractory cylinder of fire clay or other suitable material, which is provided at its lower end with a frusta-conical segregation or collection chamber A; and which is grooved at its upper end to receive a split champing ring 6, that is adjustably attached and secured to, the anged collar coupling 1, 'by the interdigitated set of leveling screws and clamp bolts 8--9, 8-9 etc. The parts B-I and 'I are further held in their proper concentric or axial association by the tubular bolt I0 whose head engages with the upper wall of the segregation chamber A, and which projects through the lower flange of the coupling 'I to receive an elongated sleeve nut II that is screwed down against the said flange after the coupling and ring members' and I have been adjusted and clamped in their desired relationship.

In order to retard the escape of the heated gases from the forehearth chamber I through the opening around the reciprocable bell B-(and thus aid in shielding the ring and coupling connections, 6--1-8-9 etc., from the heating and corrosive effects of these escaping gases) I preferably provide the roof blocks of the dog house with downwardly extending portions I2, which are formed with an enlarged opening I3, of substantially greater diameter than that of the member B; and close the upper end of this opening (I3) by means of an annular cover ring or collar I4, which ts closely around the external periphery of this reciprocable member. The annular guard chamber I3 thus formed, communicates, at its rear side (next'the tank 2), with an inclined flue lli-which is formed by the channeled roof blocks I6 and the refractory tiles II-that'leads to the vertical stack I8 on the front wall of the glass melting tank 2. In order to furtherprotect the metal supports of the reciprocating bell against any residual escape of gases through the clearance space between the parts, B-HI, I may also provide-a rectangular sheet metal hood I9, which surrounds the ring and collar assembly,

`6-'I, etc., and which is connected at .one side (by a sliding joint 20) with a stationary supply pipe 2-I, that leads to one of the usual low pressure air cooling ducts of the forming machine assembly. The current of cooling air which is I.

thus discharged into the guard box I9 escapes therefrom through a vertical vent tube, 22, which may, if desired, be connected, by another sliding joint, with a stationary pipe 23 (see dotted lines) that leads to the flue. i8. If this last described ar- ,H1-0

rangement is used the ejector action of the current of discharged cooling air will aid the natural draft of the stack ue I8, in drawing away the hot gases that ,enter the guard chamber I3 and in preventing their escape past the cover ring I4.

The upper head of the centering coupling I is bolted rigidly to the lower flanged end of `a hollow shaft 24, that is rotatably mounted in a reciprocable cross head frame, which comprises; the central tubular member 25,`the two pairs of transverse bars, 2K5-25, 2'I-2I, and thev two cylindrical side sleeves 28-29, and which are adapted to be moved up and down, 'on the vertical guide rods `3-3I, by any suitable means. In the construction, as here shown, the reciprocatory mechanism comprises an air cylinder 32 which is detaohably secured to one of the guide members 30; and a walking beam 33, which yis fulcrumed, at 3A, on a rocking link member, 35, that is supported, by an adjustable bracket `36, on the guide rod 3l. The walking beam is pivotally connected, at its center, with the reciprocable cross head frame, by the removable trunnions 3I-3'I; and is detachably engaged, kat its free end, with a collar 38, on the piston rod 39.

35 The walking beam 33 is also preferably provided with an extension arm All which carries an s adjustable counterweight 4|, that serves to partially or completely balance the weight of the cross head frame and of the bell and` bell supports carried thereby.

The reciprocation of the above described assembly is effected and controlled by the alternate admission and exhaust of compressed air to and from opposite ends of the cylinder 32, (through fthe pipe connections -46), by the usualiform of timer valve mechanism 4l .that is actuated by a cam 48 on the shaft 49 which is driven by a variable speed motor M controlled by the rheostat R. The length of stroke of the cylinder pistonand the upper and lower vlimits of that stroke-may be varied, and determined, by two adjustable stops, 56 and 5I, which are adapted to engage the head 38 on the piston rod 39; and thereby arrest the movement of the reciprocating bell support at any desired and preadjusted points in its travel. These stops are carried by a rod 52, which is slidably mounted in -a boss 53 on a cylinder block 32. The upper end of this rod is threaded to receive two lock nuts 54-54 which clamp the upper stop 5I in any desired position on the rod; and the lo-wer end thereof is similarly 'threaded to receive two other lock nuts 55-55, that serve to secure the-'rod itself in any desired position in the boss 53. The i stop alone, or the lower limit of movement may be changed- Without altering the length `of stroke-by turning the lock nuts 55 55, and thus bodily raising or lowering the rod and stop assembly as a whole. A'joint or concurrentadjust- -ment and setting lof both .pair-of lock 54-54 and 55-55, will regulate both the extreme movement and the uppermost and lowermost positions of the reciprocating bell, within such limits as are imposed by the maximum extent of piston travel.

The upper end of the hollow bolt I is connected, bythe sleeve nut Il, with the adjacent lower end of a small pipe 60, which passes upward through the hollow shaft 24 and is centered and supported, at the point where it leaves this shaft, by the threaded collar 6I. This pipe is closed at its upper end, but is provided with a small side port 62 that is positioned a short distance below the end closure. The upper portion of the pipe 60 is slidably engaged with an open ended sleeve 63 which is of suflicient length to permit this reciprocable member (Which performs the functions of the element e of Figs. 1, 2 and 3) to travel through its extreme range of movement Without uncovering the port 62. The sleeve 63 is provided with a narrow circumferential groove 64, which opens into a surrounding annular chamber B5, that is formed in the enlarged central portion of the sleeve; and this chamber communicates with the external air through a lateral port opening that can be opened or closed by the manually operable valve The sleeve is suspended from an overhead frame, 61 -68-68, by means of the two tubular (pipe). links, 69-10, which serve to support and hold the sleeve in a definite preadjusted position with respect to the reciprocating pipe member 60, and thus periodically establish a momentary connection (through the groove 64 and the port 62) between the sleeve chamber 65 and the interior of the moving bell. The ducts or passages in the hollow suspension links (S9-'i0 are connected, at their lower ends, with the sleeve chamber 65, by means of the elbow couplings, ll-1|; and are also connected, at their upper ends, with the hollow (pipe) arms 68-68, by means of the elbow joints l2-l2. The opposite extremities of the arms 68-68 are, in turn, coupled to the xed ends of two independent fluid supply conduits 13 (one of which appears in Fig. 6) by a second pair of elbow joints (T4-T4) which are similar to those (l2-J2) shown in Fig. 7 which also serve as a pivotal support, or fulcrum, for the frame assembly (il-58 etc. The tubular links 69 and lil are provided with manually controllable valves, l-16, which serve to open or close the passageways therethrough, and thus establish or shut off communication between the sleeve chamber 65 and the fluid supply conduits 'I3-73, one of which leads to a source of fluid under superatmospheric pressure, and the other of which is connected to a source of fluid under sub-atmospheric pressure (vacuum). The opening of any one of the three valves, 66, or 16 (the other two being closed) permits of the periodic equalization of the pressure in the bell chamber (A--D) with that of the external atmosphere, or with the fixed pressure in either of the fluid supply conduits 13; this periodic equalization being automatically effected whenever the port 62 in the pipe 63) is brought into registry with the groove 64 in the sleeve 63.

In order to vary the point in the bell movement at which the equalization last referred to is brought about-either at the beginning of the operation, or periodically during each up and down stroke of the reciprocating members-the frame 61-68 may be rocked upy and down, on its fulcrum support (at 14), by means `of a link and lever connection 80-*8I-82, and the hand wheel 83, which is rotatably supported on a bracket 84 extending from the lowerend of the rod member 52 and which is threaded to engage the adjacent end of the link 82. This system of connections permits of the independent adjustment of the sleeve member (63) with respect to the reciprocable members (B-60 etc.)- so as to establish a. desired pressure, (and trap a predetermined quantity or mass of elastic fluid) in the bell chamber (D) at any predetermined point in the up and down movement of the latter-or `of a conjoint adjustment of the sleeve member and the bell members,such as may result from the resetting of the lock nuts 55-55, and the consequent variation and regulation of the lower limit. of bell movement.

It is a further purpose of my present improvements to establish and maintain substantial uniformity of temperature in the outflowing stream of molten glass. In order to accomplish this object I preferably use a forehearth which is relatively short (i. e. which extends only a small distance from the front wall of the main tank), and which is provided (as shown in Fig. 4) with an upwardly inclined roof portion I6 that permits me to secure a large unobstructed opening between the forehearth chamber and the large main tank chamber, in which the temperature conditions are less subject to sudden fluctuationsand are less affected by outside influences-than is the case in a relatively small, and more or less isolated, extension thereof. The flow of glass from the main tank to the forehearth is, in this case, controlled or throttled by a floating skimmer block 8l, which is normally held away from the threshold of the forehearth floor, by any suitable means, but which can, when occasion arises, be allowed to move up against this threshold and thus shut off entirely the further flow of glass thereover.

The up and down movement of the bell B serves to agitate and stir the mass of molten glass in which it is immersed, and thus aids in maintaining uniformity in temperature conditions therein. This eiect may besupplemented, if desired, by also imparting a rotary movement to the reciprocating member B. This, is accomplished by providing the upper end of the supporting shaft 24 with a spur gear, 90, which is operatively connected with an elongated spur pinion 93, on the motor shaft 49, by means of the two idle gears 9|, 92 that are rotatably mounted on, and carried by, the cross head frame members, 21-21-28 etc.

One of the features of operation which is characteristic of my improved feeder is the elimination of any intervals of completely arrested fioW--or of any lifting of the glass with respect tothe severing means-and this makes it desirable to provide a shear mechanism S (for cutting off successive mold charges from the constantly flowing stream) that will operate with such speed that there is no opportunity for the oncoming glass to pile up on the shear blades and unduly heat the latter.

The shear mechanism S is preferably of the type disclosed in my copending application Serial No. 701,636, filed December 9, 1933, and in general comprises a pairof shear blades which are detachably mounted on two arms or heads 91--98 that are, in turn, respectively, secured to and revolve with a shaft and concentric sleeve having beveled pinions H13- 04 keyed thereto respectively, which are engaged by bevel gear |05. The

bevel gear |05 is rotated to revolve the shear 75 blades by a suitable cylinder having an operating piston therein which is driven in-one direction by fluid pressure delivered to the cylinder through the conduit |20 in response to the operation of the timer valve |2I by the cam |22 on the motor-driven shaft 48, and the piston is returned to its initial position by the tension springs I 41. The shear mechanism S is supported as a unit on an adjustable arm |42 which can be rigidly clamped to the posts 4.

The reciprocable bell member B may be readily lifted out of the forehearth by disconnecting the air line and stack fiue connections 2| and 23, uncoupling the union joints in the pipe lines 69 and 10, and removing the pintle pin 34; and then raising the entire cross head assembly 24--25-26-21 etc., by means of two cables Viti-|10 that are attached to a suitable hoisting mechanism (not here shown). The upward movement of the cross head carriage will automatically disengage the forked end of the walking beam 33 from the piston rod head 38; and the removal and replacement of the suspended bell (B) may be effected without disturbing any of the various adjustments which have been previously described.

The shaft 49 which actuates the timer valve mechanisms, lil-|38, |2|-|22, and also serves to rotate the bell member B-s driven, through suitable reduction gearing, by a variable speed motor M, that is controlled by a manually operable rheostat R. If the feeder is to be used with a forming press (or press and blow) machine of the usual character, the latter should be operated in synchronisin with the formation and severance of successive mold charges; and this may be done either by a mechanical connection between the shaft 49 and the operating mechanism of the forming machine, or by the provision of an additional timer valve device (similar to that indicated at 41). for pneumatically actuating the said mechanism. The construction of these timer valve devices, and the manner in which they may be used for the purposes indicated, are so well known Yto'those skilled in this art that no description of them is necessary.

Various other details of construction, which are illustrated in the drawings, but which may not have been specifically referred to or described, will be readily understood, and if necessary elaborated," by glass house engineers; and with the above disclosures as a guide, those familiar with other types of glass feeder apparatus can readily design alternative and equivalent forms of construction which will operate in accordance with principles hereinbefore explained, and which will embody, in whole or in part, as maybe desired, the features of my present improvements. The accompanying drawings illustrate only one of various structural assemblies which I have designed for the purpose of practicing my invention; and the invention itself is therefore to be limited only as indicated by the language and the scope of the appended claims.

What I claim as new'and desire to secure by Letters Patent is:

1. An improvement in the art of feeding glass from a submerged orifice which comprises the successive steps, of admitting a limited quantity of the molten material to the lower end of an inverted cup-shaped receptacle that is positioned above and adjacent tosaid orifice, placing the upper end of said receptacle in momentary communication with a source of substantially con- 'stant fluid pressure, interrupting this communication, progressively varying the pressure in the confined fluid by reciprocating the cup and thereby regulating the outflow of glass from the subjacent orifice, and establishing hydrostatic equilibriurrbetween the interior and exterior of said receptacle at each end of its reciprocatory stroke.

2. An improvement in the art of feeding glass from a submerged delivery orifice which comprises the steps of inducing a flow from a parent body of the molten material into the lower end of a bell-shaped receptacle positioned above said orifice, trapping a predetermined quantity of an elastic fluid in the upper portion of said receptacle, and varying the rate of outflow from the said orifice by periodically reciprocating said receptacle at a speed sufcient to cause the movement of the molten glass therein to lag behindY the movement of said receptacle to thereby increase and decrease the pressure of the trapped fluid and concurrently decrease and increase the resistance to return flow from the receptacle to the parent body of material.

3. A method of feeding molten glass, which consists in accumulating a mass of molten glass above a submerged now orifice, segregating a portion of such mass above such orifice, trapping a mass of elastic fluid above such segregated porl tion, and varying the pressure of such trapped mass by moving such segregated portion toward and away from such orifice, and periodically establishing hydrostatic equilibrium between the segregated portion and the mass of glass.

4. A method for feeding of glass from a large parent body through an orifice submerged by the molten material, which consists in confining a mass of such material in an inverted cup-shaped retainer partially submerged in the parent body and positioned above the submerged delivery orifice, admitting a predetermined mass of elastic fluid to the upper end of said container and confining it therein, and periodically reciprocating said container to vary its degree of submergence in the glass and thereby vary the pressure of the confined mass of elastic fluid on the glass above the orifice.

5. A method of feeding of glass from a continuous source of supply, which consists in admitting a limited quantity of the molten material to the lower portion of an inverted cup-shaped receptacle, containing a predetermined and xed quantity of elastic fiuid, and periodically moving said receptacle toward and away from a submerged discharge orifice positioned therebeneath, to thereby vary hte volume and pressure of the confined fluid and concurrently vary the area of the admission passage leading from the said source of supply to the said receptacle.

6. A method for continuously feeding molten glass from a parent body through an orifice submerged by the molten material, which consists in confining a limited mass of material in a bellshaped receptacle having its lower end constantly submerged in the said `parent body, admitting a predetermined mass of elastic fiuid to .the upper end of said receptacle above the confined material and trapping it therein, and periodically moving said bell toward and away from said orifice, to thereby alter the flow of glass therefrom.

- 7. An apparatus for the delivery of a stream of glass at a periodically Variable rate of ow which comprises a heated receptacle for the molten material having a submerged delivery orifice, an inverted cup-shaped container positioned above said delivery orifice and projecting into the molten material within said receptacle, a passageway leading from said receptacle tothe lower end of said co-ntainer, means for reciprocating said container to vary the area of said passageway, a second passageway leading from the upper end of said container to a source of substantially uniform fluid pressure, and means responsive to the reciprocating movement of said container in each direction for both opening and closing the last mentioned passage to trap a predetermined quantity of fluid pressure in said container intermediate the ends of its travel.

8. The method of feeding molten glass from a submerged orifice having a movable bell-shaped container disposed thereabove, which consists in segregating a mass of molten glass in said container, trapping and confining a mass of elastic fluid in said container above such segregated mass, moving said .container toward said orifice to decrease the volume and increase the pressure of such trapped mass of elastic fluid and progressively accelerate the flow through said orifice while concurrently increasing the resistance of fiow from said segregated mass to the parent body, continuing the accelerated fiow through said orifice after such container has come to rest in its lowermost position, and then moving said .container away from said orifice to increase the volume and decrease the pressure of such trapped fluid to diminish the flow of glass through sai-d orifice. 9. A method of feeding molten glass from a submerged orifice which consists in occasioning a flow of glass from a parent body to an inverted bell, confining and trapping a predetermined mass of elastic fluid in said bell above said segregated mass, periodically moving said bell toward said orifice to progressively decrease the volume and increase the pressure of such trapped 40 mass of fluid to accelerate the flow through such orifice and increase the resistance of return flow from such bell to the parent body, utilizing the pressure built up in said bell to continue the accelerated flow through said orifice after the bell has come to rest, moving said bell away from the orifice to momentarily diminish the fiow through said orifice and continuing the movement of said bell away from the orifice to increase the volume and decrease the pressure of such trapped mass of fluid and reestablish the flow from said parent body to said orifice.

10. A method of feeding molten glass from a submerged orifice having a movable bell-shaped container disposed thereabove which consists in segregating a mass of molten glass in said container, trapping and confining a mass lof elastic fluid in said container above said segregated mass, reciprocating said container to progressively vary thepressure of the trapped fiuid in said container and establishing hydrostatic equilibrium between the segregated mass and the parent body at each end of the reciprocatory movement of said container.

11. A method of feeding molten glass in a suspended stream through an orifice submerged by amount of glass discharged through the orifice' by regulating the quantity of elastic fluid trapped within the bell.

12. A method of feeding molten glass through an orifice submerged by a body of such material which consists in confining a portion of the glass above the orifice within a hollow implement, trapping a fixed quantity of elastic fluid above the confined portion within the implement, moving said implement toward said orifice to compress the fluid within said implement and concurrently prevent a flow from the implement to the supply body and then moving said implement away from said orifice to expand the quantity of elastic fiuid within the implement and establish a free flow from the parent body to the orifice.

13. A method of feeding molten glass through an orifice submerged by a body of such material which consists in confining a portion of the material above said orifice in a bell, trapping a predetermined quantity of elastic fiuid in said bell, and progressively compressing and expanding the fiuid within said bell by reciprocating said bell.

14. A method of feeding molten glass through an orifice submerged by a supply of such material Which consists in establishing a gravityflow of material from the supply through the orifice, confining a portion ofthe glass above the orifice within a bell projecting into the supply body, trapping a fixed mass of elastic fluid within said bell, continuously reciprocating said bell to alternately expand and compress the fluid trapped therein and decrease and increase the resistance of flow from the supply body to the orifice to alternately decelerate and accelerate the fiow of l' glass through the orifice.

15. The method of operating a glass feeder having a bell reciprocably mounted above an orifice submerged by a body of such material which consists in continuously reciprocating said bell to alternately restrict and increase the area of the passage between the supply body and the orifice, trapping a predetermined mass of elastic fluid within said bell at one point in its cycle of movement, and compressing and expanding the trapped fiuid by the continued movement of the bell to periodically accelerate and decelerate the fiow through the orifice.

16. The method of operating a glass feeder having a bell reciprocably mounted above an orifice submerged by a body of such material which consists in continuously reciprocating said bell to alternately restrict and increase the area of the passage between the body and the orifice, trapping a predeterminedV mass ,of elastic fluid within said bell at one point in its cycle of movement, compressing and expanding the trapped fluid by the continued movement of the bell to periodically accelerate and decelerate the flow through the orifice, and utilizing the pressure created by the compressing of the elastic iiuid to continue the accelerated flow after the termination of the downstroke of the bell.

17. 'Ihe combination in ay feeder for molten glass comprising a forehearth for molten glass having a submerged orifice in the floor and a flue in the roof thereof, a bell projecting through an opening in the roof of said forehearth and extending into the glass over said orifice, means for reciprocating said bell to kcontrol the flow through the orifice, means for introducing heating gases into the forehearth to maintain the glass therein at the desired Working temperature, an annular collection chamber surrounding said bell and communicating with said flue for retarding the escape of heated gases from said orehearth, and means for directing a cooling fluid over the upper end of said bell and discharging it into said flue.

18. The combination in a feeder for molten glass comprising a forehearth for molten glass having an orifice in the floor and an enlarged opening in the roof thereof, a bell adapted to control the flow through said orifice projecting through said roof opening and extending into the glass Within said forehearth, means' cooperating With said bell for substantially closing the upper end of said roof opening to provide an annular chamber in said roof and surrounding said bell, a ue in said roof for establishing communication between said annular chamber and a suitable stack to Withdraw the heated gases collected therein, and means for directing a cooling fluid over the upper end of said bell and discharging it into such stack.

19. A feeder for molten glass comprising a forehearth having an open flow oriiioe in the bottom thereof, a bell projecting into said forehearth and extending into the glass therein, a tube secured to said bell and having one end closed and the other communicating with the interior of said bell, a port in said tube, and means for reciprocating said bell to move said port into and out of communication With a source of elastic fluid pressure during the movement of the bell in each direction.

20. A feeder for molten glass comprising a forehearth for molten glass having an open oW orice in the bottom thereof, a bell projecting into said forehearth and extending into the glass contained therein, a ported tube secured to said bell and in communication With the interior thereof, a sleeve surrounding said tube and having an open chamber therein, means for connecting said sleeve chamber to a source of elastic fluid and means for reciprocating said bell to move the port in said tube into and out of communication With said open chamber to momentarily connect the interior of said bell to the source of elastic fluid whereby a predetermined quantity of such iiuid is trapped in the bell during its movement in each direction.

21. A feeder comprising a forehearth for molten glass having a submerged flow orifice, a bell extending into the glass contained in said forehearth, a ported tube secured to said bell and communicating with the interior thereof, a sleeve surrounding said tube and having an open chamber therein, means for connecting the sleeve chamber to a source of elastic fluid maintained under substantially constant pressure, means for reciprocating said bell to move the port in said tube into and out of communication with said open chamber to momentarily connect the interior of said bell to the source of elastic fluid whereby a predetermined quantity of such uid is trapped in the bell during its movement in each direction, and means for adjusting said sleeve to vary the position of said sleeve chamber relative to said port.

FRANK L. O. WADSWORTH. 

